Metro

It was finally constructed about a century after most of its European counterparts, but for that same reason, Athens has one of the most luxurious and squeaky clean metro systems in Europe. It only has two lines (plus a pre-existing one which runs over-ground) but its stations are lined with marble and granite and are generously and tastefully adorned with artworks and replicas of ancient objects (in some cases, even showcasing original archaeological material). Syntagma and Acropolis stations are the most interesting and well-worth a visit.